Ryu sits next to 3 phonetic neighbors — Drew, Lew, and Rue are the closest matches by sound. Most share Ryu's Japanese cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"flow, current, stream"
"from the west farm"
"river traveler"
"old town, settlement"
"exalted, high place"
"ray of light, beam of sunlight"
"king, ruler"
"remembered by God"
"God has exalted (Jah + kai)"
"from the town, settlement"
"oracle, mouth of the serpent"
"associated with luxury and elegance"
"from the place of wide waters"
"archer, yew-wood man"
"belonging to God"
"little warrior; little of Mars"
"supplanter, he who follows at the heel"
"modern American coinage, bright day"
"beloved, dear one"
"part of Lord Shiva"
"God is gracious (via Sean/Shawn/John)"
Similar sound: These names share phonetic patterns with Ryu — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Japanese origins, giving them the same cultural heritage as Ryu.
Rhythm: Ryu is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.